When the equation below is correctly balanced, the coefficient for CO2 is

The answer to your question is 4

Explanation:

Chemical reaction

                C₂H₆  +  O₂  ⇒  CO₂  +  H₂O

           Reactants    Elements    Products

                  2            Carbon              1

                  6            Hydrogen         2

                  2            Oxygen             3

Balanced chemical reaction

                2C₂H₆  +  7O₂  ⇒  4CO₂  +  6H₂O

           Reactants    Elements    Products

                  4            Carbon             4

                 12            Hydrogen       12

                 14            Oxygen           14

When the reaction is balanced the coefficient for CO₂ is 4.

the seeing the electronic configuration we can say that the element is fluorine.

fluorine is the most electronegative element in the periodic table.

but by only seeing the configuration we cannot say about its reactivity because we don't know if its configuration after excitation or by addition of electrons.

but if not then, it is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. as the most electronegative element, it is extremely reactive: almost all other elements, including some noble gases, form compounds with fluorine.